Actually, there are two complete sets of instructions in the Get Help section of Family Tree that explain, in detail, how to unmerge and uncombine records. Before jumping into this type of situation, it is imperative that you take the time to study the procedures carefully so that you can successfully correct the Family Tree record. The types of problems addressed by these procedures are listed in the a Get Help article entitled, "Dividing incorrectly combined records in Family Tree" and in more detail in the Family Tree Training Lessons and Videos section of the Learning Center.
From the Get Help - Help Center article, here is a list of the issues addressed:
Separating incorrectly merged records is explained in a separate article entitled, appropriately enough, "Undoing a merge." The main catch to this process is the warning that if changes have been made to the record since the merge, the Unmerge button will be visible. In this case, you will need to click on the blue name of the deleted person, open their person card and restore the person. I suggest that you really must read the instructions about this issue carefully and follow the instruction equally as carefully.
- A Family Tree record represents two similar but distinct individuals.
- The record is about a completely different person who is linked into the family by mistake.
- The record was incorrectly merged in Family Tree.
- The record was incorrectly combined in new.familysearch.org and moved to Family Tree.
- Ordinances can be adversely affected.
- Ordinances for the newly created person are buried in the incorrectly combined record.
- Can FamilySearch find the ordinances and restore them to Family Tree?
- How do I restore the ordinances to avoid duplication?
Undoing a combined record from New.FamilySearch.org is a much more complicated procedure. Until you become very familiar with this process, you will need to carefully follow the rather complicated instructions. I strongly recommend working through the lessons in the Family Tree Training Lessons and Videos to give yourself the necessary background in working with the Family Tree program so that you can understand what has happened and what will happen with an incorrectly combined record. From the article cited above, here is an explanation of the problem:
Ancestral File was a database that listed the names and vital information of millions of individuals, organized into pedigrees. The information was taken from pedigree charts and family group records submitted to the Family History Department beginning in 1978. When the database for new.FamilySearch.org was created, submissions from Ancestral File were sometimes incorrectly combined with each other or with new submissions in new.FamilySearch.org to create a single record for two similar but distinct persons. In new.FamilySearch.org, users could separate combined records, but the Separate feature seldom corrected all of the errors. In fact, sometimes it caused more errors. Consequently, new.FamilySearch.org has become read only. Unfortunately, the incorrectly combined records from new.FamilySearch.org are displayed in Family Tree.The article goes on to explain how to identify badly combined records in Family Tree and gives detailed instructions (the same as those in the Family Tree Training Lessons and Videos, that are needed to rectify the problems.